WO2021115749A1 - Method for producing a marked polymer, marker, use of the marker, and marked polymer - Google Patents

Abstract

The invention relates to a method for producing a marked polymer. The method comprises mixing polymer precursors with a marker and polymerising the polymer precursors, producing a marked polymer, or alternatively mixing a polymer with a marker, producing a marked polymer. The method is characterised in that the marker contains or consists of particles which contain or consist of a metal and/or a semi-metal, the marker having at least three atom types with a different atomic number. The invention also relates to a marker and to a marked polymer. Uses of the marker according to the invention are also proposed. The marker according to the invention does not significantly influence the properties of the polymer and enables coded information to be read out of a wide variety of polymers in a quick and simple manner and over long lifespans of the polymer.

Description

Method of making a labeled polymer, marker. Using the marker and labeled polymer

A method for making a labeled polymer is presented. The method comprises mixing polymer precursors with a marker and polymerizing the polymer precursors to form a labeled polymer or, alternatively, mixing a polymer with a marker to form a labeled polymer. The method is characterized in that the marker contains or consists of particles which contain or consist of a metal and / or a semimetal, the marker having at least three types of atoms which have a different atomic number. A marker and a labeled polymer are also provided. In addition, uses of the marker according to the invention are proposed. The marker according to the invention does not significantly influence the properties of the polymer and allows coded information to be read out in a wide variety of ways

Polymers in a simple and fast way and over a long lifetime of the polymer. The marking of batches of plastics (polymers) is a major challenge due to the large number of available types of plastics. Based on the granulate or any part of the component, no conclusions can be drawn about the type and manufacturer of the material. However, this is essential from the point of view of material / product authenticity as well as aspects of the circular economy of plastic products.

Decisive for the practical use of such a marking are its durability over the product life, the embeddable information content, readability of the information, the size of the marker element and thus a possible interaction with the target properties of the material.

From the problem, i.e. the marking of plastic batches, the first goal is that the markers should be long-term resistant and should be suitable to outlast the processing and shaping process and the period of use. Furthermore, the information content that can be mapped in the marker should be sufficiently high to be able to differentiate between a large number of plastic types and batches. In addition, the information encoded by the marker should also be able to be read out quickly and easily from different plastic compositions. In addition, the marker should not have any noticeable impact on the properties of the product.

Plastics are usually not marked to this day. In the context of the increasing importance of the circular economy and of questions in the area of product authenticity, however, the need for practical marking processes is growing. When marking plastics, fluorescence-based approaches, such as the introduction of organic fluorescent paints, special fluorescent nanoparticles or the inherent fluorescence of the plastic itself, have so far been pursued. Material-specific decay times or intensity maxima at characteristic wavelengths in the visible range are used for identification based on fluorescent colors. Due to the width of the spectral distribution of the flux reflected back from the plastic orescent light, however, the information content that can be reproduced is limited. In addition, a decrease in fluorescence intensity is to be expected in the course of the processing process and over the life of the product. This is especially true for organic fluorescent markers.

The intrinsic fluorescence of plastics is currently used for sorting in the field of waste management. For the latter application, methods of hyperspectral image processing in the wavelength range of e.g. 900 - 1700 nm have recently been mentioned, which can identify a material, but no specific marking, i.e. no "storage" of defined information, is possible.

For the marking of plastics, there are initial studies that deal with the introduction of macromolecules, the microstructure of which is specifically synthesized as binary-coded information. The synthesis of such macromolecules and the reading of the information by tandem mass spectroscopy (MS / MS) is known in the prior art. Here, the macromolecules are added during the synthesis of the functional polymer or introduced into the polymer as a second variant by swelling. The extraction from the polymer and the enrichment of the macromolecular markers has so far been a prerequisite for reading out (reading back) the marker information. However, reading out is currently not possible within a complex polymer mixture.

Starting from this, the object of the present invention was to provide a method by means of which a marked polymer can be provided which no longer has the disadvantages known in the prior art. In particular, the polymer provided should have a marker that is stable with respect to the polymer production process and processing process, does not significantly affect the properties of the polymer and allows the information encoded by the marker to be read out in a wide variety of polymer types in a simple and fast manner and over a long period of time Lifetime of the polymer enables. Furthermore, such a labeled polymer should be provided and uses thereof suggested. The object is achieved by the method with the features of claim 1, the marker with the features of claim 9, the use of the marker with the features of claim 16 and the marked polymer with the features of claim 17. The dependent claims show advantageous Embodiments on.

According to the invention, a method for producing a marked polymer is provided, comprising the steps a) mixing polymer precursors with a marker and polymerizing the polymer precursors, a marked polymer being formed; or b) mixing a polymer with a marker to form a labeled polymer; characterized in that the marker contains or consists of particles which contain or consist of a metal and / or a semimetal, the marker (for example each particle of the marker) having at least three types of atoms which have a different atomic number.

Metal is understood to mean in particular an elemental metal (e.g. Cu), whereby this also includes alloys and / or mixtures of elemental metals (e.g. a ternary metal alloy). Semimetal is understood to mean in particular an elementary semimetal (e.g. Si), whereby here also mixtures of elementary semimetals are understood. Metal or semimetal is therefore in particular not understood to mean any chemical compounds of metals or semimetals, for example no metal oxides (e.g. CuO) and no semimetal oxides (e.g. S1O2). Nevertheless, for example, at least one ceramic can be a further component of the marker.

Using the method according to the invention, a marked polymer can be provided which contains a processing-stable marker which does not significantly influence the properties of the polymer and which enables coded information to be read out in a wide variety of polymers in a simple and fast manner and over a long service life of the polymer enables. For the first time, plastic batches can be marked with a relatively large number of variations, ie with a high information content, right from production. The marked polymer provided allows stable traceability of the polymer to the starting material and also to the manufacturer.

In contrast to the fluorescence-based markers used in the prior art, a higher number of information bits can be used which, moreover, do not overlap. In addition, in contrast to the fluorescence-based markers used in the prior art, there is no so-called "photobleaching", which significantly increases the long-term stability of the information encoded in the marker. There is also no thermal decomposition of the markers that would otherwise occur with fluorescence-based markers The prior art is observed at higher processing temperatures.This circumstance also significantly extends the long-term stability of the information encoded in the marker compared to known labeled polymers from the prior art.

The method according to the invention can be characterized in that the marker contains or consists of a metal, preferably contains or consists of a mixture of different metals and / or a metal alloy, preferably contains or consists of a metal alloy. The advantage here is that metal atoms can easily be detected using X-ray fluorescence analysis. The information encoded in the marker can thus be read out quickly and easily.

Furthermore, the marker can contain or consist of a semimetal. Semi-metals (e.g. silicon) as a marker component have the advantage that they can be easily modified geometrically (e.g. writing a barcode using lithography) and / or chemically (e.g. doping), which makes it easy to increase the information content encoded in the marker.

Apart from that, the marker can also contain a ceramic. Ceramics as a marker component have the advantage that they are resistant to high temperatures and have a high degree of hardness. As a result, these marker components allow high long-term stability even under harsh processing conditions for the polymers. In a preferred embodiment, the marker is suitable for detection by means of X-ray fluorescence. X-ray fluorescence is a trace analysis method that is highly sensitive to metal-containing fillers in organic polymers. The detection limit of X-ray fluorescence is around one ppm. In addition, the information from the marker can be read out quickly and easily using the X-ray fluorescence.

In a preferred embodiment, the marker does not have any atom types which originate from a catalyst which is used to catalyze the polymerization in step a) and / or is contained in the polymer from step b). The advantage here is that the information encoded in the marker is independent of the manufacturing process of the polymers and the information is not overlaid by unknown external information. This makes it easier to correctly assign the marker information that has been read to a specific polymer.

In a further preferred embodiment, the marker does not have any atom types that originate from a wall of a container and / or a processing machine that is used in the polymerization in step a) and / or used in a production of the polymer from step b) has been. The advantage here is that the information encoded in the marker is independent of the manufacturing process of the polymers and the information is not overlaid by unknown external information. This makes it easier to correctly assign the marker information that has been read to a specific polymer.

The marker can be modified geometrically. The marker is preferably geometrically modified in such a way that it has a geometrical profile in the surface. Furthermore, the marker can have been processed using a method selected from the group consisting of lithography, laser beam treatment, electron beam treatment, etching methods and combinations thereof. In addition, the marker can have an inscribed pattern, preferably an engraved and / or lithographically generated code, particularly preferably an engraved and / or lithographically generated barcode and / or point code. The additional geometric mo- Dification of the marker has the advantage that additional coding levels are introduced and the information content of the marker is increased as a result. For example, the geometric modification of the manufacturer, index values, batch numbers, the year of manufacture or the date of manufacture of the polymer can be coded.

The marker can be chemically modified. The marker is preferably chemically modified in such a way that it has a chemically generated profile on the surface. Furthermore, the marker can be selected from the group consisting of chemical activation of the particles, physical activation of the particles, covalent binding of molecules to the particles, doping, ion implantation in the particles, binding of nanodots to the particles, and combinations have been processed by this. In addition, the marker can have or consist of nanodots, optionally having nanodots that are chemically covalently bonded to the particles. Apart from that, the marker can have a chemical pattern. The chemical modification of the marker has the advantage that additional coding levels are introduced and the information content of the marker is increased as a result. For example, the geometric modification of the manufacturer, index values, batch numbers or the year or date of manufacture of the polymer can be coded.

The marker can be admixed in the process in an amount such that the marked polymer has 1 ppm to 1000 ppm marker, preferably 2 to 900 ppm marker, particularly preferably 5 to 800 ppm marker, particularly preferably 10 to 700 ppm marker, very particularly preferably 20 to 600 ppm marker, in particular special 50 to 500 ppm marker, based on the total amount of the labeled polymer. An addition of the marker in a larger amount can be advantageous in order to contrast the signal of the marker with respect to types of atoms which have inevitably got into the polymer as a result of the production process of the polymer. Correct assignment of the marker information read out to a specific polymer is thus made easier.

Furthermore, the marker used in the method can measure particles having a particle size in the range from 1 nm to 1000 miti, preferably 500 nm to 10 miti, particularly preferably 0.1 miti to 5 miti, in particular 1 miti to 5 miti, measured with a microscopic imaging process, contain or consist of them. Larger particles have the advantage that they can store a higher information content, for example after a geometric and / or chemical modification. In addition, larger particles allow a difference to the components of the polymer that got into the polymer via the manufacturing process (eg catalyst salts and / or catalyst complexes) to be determined. This makes it easier to correctly assign the marker information that has been read to a specific polymer.

According to the invention, a marker is also provided which contains or consists of particles, the particles containing or consisting of a metal and / or a semimetal, the marker (for example each particle of the marker) having at least three types of atoms, which are different Have atomic number and the marker is characterized in that it is geometrically modified and / or chemically modified.

The marker can be characterized in that it contains or consists of a mixture of different metals and / or a metal alloy, preferably contains or consists of a metal alloy.

Furthermore, the marker can be characterized in that it contains or consists of a semi-metal.

In addition, the marker can be characterized in that it also contains a ceramic.

In addition, the marker can be suitable for detection by means of X-ray fluorescence.

In a preferred embodiment, the marker does not have any types of atoms that originate from a catalyst that is used to catalyze a polymerization of a polymer and / or is contained in a polymer.

In a further preferred embodiment, the marker does not have any types of atoms that originate from a container wall of a container that is used in the production of a polymer. The marker can be geometrically modified, preferably in such a way that it has a geometrical profile in the surface. Furthermore, the marker can have been processed using a method selected from the group consisting of lithography on the particles, laser beam treatment on the particles, electron beam treatment on the particles, etching methods and combinations thereof. Apart from this, the marker can have an inscribed pattern, preferably have an engraved and / or lithographically generated code, particularly preferably an engraved and / or lithographically generated barcode and / or point code.

In addition, the marker can be chemically modified, preferably such that it has a chemically generated profile on the surface. The marker can also be processed using a method selected from the group consisting of chemical activation of the particles, physical activation of the particles, covalent binding of molecules to the particles, doping, ion implantation in the particles, binding of nanodots to the particles, and combinations thereof have been. Apart from this, the marker can have or consist of nanodots, optionally have nanodots that are chemically covalently bonded to the particles. In addition, the marker can have a chemical pattern.

The marker can be characterized in that it measures particles which have a particle size in the range from 1 nm to 1000 miti, preferably 500 nm to 10 miti, particularly preferably 0.1 miti to 5 miti, in particular 1 miti to 5 miti with a microscopic imaging technique, contains or consists of.

The use of the marker according to the invention for identifying a polymer (ie a polymer to which the marker has been added) is proposed, the identification preferably taking place via X-ray fluorescence and / or a microscopic method. In particular, the identification of the polymer is used to assign the polymer to a specific manufacturer, preferably to assign it to a specific batch from a specific manufacturer. The identification of the polymer can also be used to identify the polymer in the context of polymer recycling. Furthermore, the identification of the polymer can be used to identify the polymer as part of a Separate polymer recycling from other polymers. In addition, the identification of the polymer can be used to document the history of the polymer.

According to the invention, a marked polymer is also provided which is characterized in that it contains a marker, the marker containing or consisting of particles which contain or consist of a metal and / or a semimetal, the marker (for example each particle of the marker) has at least three types of atoms, which have a different

10 have chemical ordinal number, the marker being modified in particular geometrically and / or chemically modified.

The marked polymer can be characterized in that it can be produced using the method according to the invention. Consequently, the labeled polymer

15 have all the features that are inevitably present in the marked polymer when the method according to the invention is carried out for its production.

The subject matter according to the invention is intended to be based on the following examples

20 are explained in more detail without wishing to restrict it to the specific embodiments shown here.

Example 1 - Preparation of a Polymer Marked with Metal Alloy Particles

25th

The various polymers PA6, PA66, PET and iPP are each mixed with a different powder of a metal alloy on a ppm scale, each powder having a metal alloy with three different metal atoms, i.e. a ternary metal alloy. Mixing in the powder

BO can take place, for example, in the course of the synthesis of the various polymers in the solution or in the course of the extrusion process of the various polymers in the production of granules.

The different polymers can thus be clearly identified via X-ray fluorescence

35 can be identified because each of the different polymers has a clearly identifiable X-ray fluorescence spectrum. Example 2 - Preparation of a Polymer Marked with Semimetal Particles

As a first step, binary information (e.g. a barcode) is written into a silicon wafer (e.g. via lithography, a laser beam and / or an electron beam), which can be read out microscopically. Furthermore, the silicon wafer can optionally also be chemically modified (e.g. via doping) in order to encode further information in the silicon wafer.

In this example, the silicon wafer is coated on the back with a layer of a metal alloy that encodes additional information, for example an assignment of a certain type of polymer or an indication that the marker in the polymer has additional information which in this case is in the silicon component of the Marker is coded.

The silicon wafers are then transferred into a particulate marker (marker powder), e.g. by grinding. In this case, the particles not only have the metal alloy, but also a silicon component that contains the barcode.

The metallic and semi-metallic components of the marker can be read out quickly using X-ray fluorescence analysis. Another method (e.g. a microscopic method) can also be used to read the barcode of the silicon component of the marker.

Claims

Claims 1. A method for producing a labeled polymer, comprising the steps of a) mixing polymer precursors with a marker and polymerizing the polymer precursors, a labeled polymer being ent; or b) mixing a polymer with a marker to form a labeled polymer; characterized in that the marker contains or consists of particles which contain or consist of a metal and / or a semimetal, the marker having at least three types of atoms which have a different atomic number. 2. The method according to the preceding claim, characterized in that the marker i) contains or consists of a metal, preferably contains or consists of a mixture of different metals and / or a metal alloy, preferably contains or consists of a metal alloy; and / or ii) contains or consists of a semimetal; and / or iii) contains a ceramic; and / or iv) is suitable for detection by means of X-ray fluorescence. Method according to one of the preceding claims, characterized in that the marker does not have any atom types which originate from a catalyst which is used to catalyze the polymerization in step a) and / or is contained in the polymer from step b). 4. The method according to any one of the preceding claims, characterized in that the marker does not have any types of atoms that originate from a wall of a container and / or a processing machine that is used in the polymerization in step a) and / or in a production of the polymer from step b) was used. 5. The method according to any one of the preceding claims, characterized in that the marker is geometrically modified, preferably such that it i) has a geometric profile in the surface; and / or ii) was processed using a method selected from the group consisting of lithography on the particles, laser beam treatment on the particles, electron beam treatment on the particles, etching methods and combinations thereof; and / or iii) has an inscribed pattern, preferably has an engraved and / or lithographically generated code, particularly preferably has an engraved and / or lithographically generated barcode and / or point code. 6. The method according to any one of the preceding claims, characterized in that the marker is chemically modified, preferably such that it i) has a chemically generated profile on the surface; and / or ii) via a method selected from the group consisting of chemical activation of the particles, physical activation of the particles, covalent attachment of molecules to the particles, doping, ion implantation into the particles, attachment of nanodots to the particles, and combinations thereof has been edited; and or iii) has or consists of nanodots, optionally having nanodots which are chemically covalently bonded to the particles; and / or iv) has a chemical pattern. 7. The method according to any one of the preceding claims, characterized in that the marker is added in an amount that the marked polymer 1 ppm to 1000 ppm marker, preferably 2 to 900 ppm marker, particularly preferably 5 to 800 ppm marker, especially preferably 10 to 700 ppm marker, very particularly preferably 20 to 600 ppm marker, in particular 50 to 500 ppm marker, based on the total amount of the labeled polymer. 8. The method according to any one of the preceding claims, characterized in that the marker particles which have a particle size in the Be rich from 1 nm to 1000 miti, preferably 500 nm to 10 miti, particularly preferably 0.1 miti to 5 miti, in particular 1 miti to 5 miti, measured with a microscopic imaging technique, contains or consists of it. 9. A marker that contains or consists of particles, the particles containing or consisting of a metal and / or a semimetal, the marker having at least three types of atoms which have a different atomic number, characterized in that the marker is geometrically modified and / or is chemically modified. 10. Marker according to claim 9, characterized in that the marker i) contains or consists of a mixture of different metals and / or a metal alloy, preferably a metal alloy contains or consists of it; and / or ii) contains or consists of a semimetal; and / or iii) contains a ceramic; and / or iv) is suitable for detection by means of X-ray fluorescence. 11. Marker according to one of claims 9 or 10, characterized in that the marker does not have any types of atoms which originate from a catalyst which is used to catalyze a polymerization of a polymer and / or is contained in a polymer. 12. Marker according to one of claims 9 to 11, characterized in that the marker does not have any types of atoms which originate from a container wall of a container which is used in the production of a polymer. 13. Marker according to one of claims 9 to 12, characterized in that the marker is geometrically modified, preferably such that it i) has a geometric profile in the surface; and / or ii) was processed using a method selected from the group consisting of lithography on the particles, laser beam treatment on the particles, electron beam treatment on the particles, etching methods and combinations thereof; and / or iii) has an inscribed pattern, preferably has an engraved and / or lithographically generated code, particularly preferably has an engraved and / or lithographically generated barcode and / or point code. 14. Marker according to one of claims 9 to 13, characterized in that the marker is chemically modified, preferably such that it i) has a chemically generated profile on the surface; and / or ii) via a method selected from the group consisting of chemical activation of the particles, physical activation of the particles, covalent attachment of molecules to the particles, doping, ion implantation into the particles, attachment of nanodots to the particles, and combinations thereof has been edited; and or iii) has or consists of nanodots, optionally having nanodots which are chemically covalently bonded to the particles; and / or iv) has a chemical pattern. 15. Marker according to one of claims 9 to 14, characterized in that the marker is particles which have a particle size in the range from 1 nm to 1000 miti, preferably 500 nm to 10 miti, particularly preferably 0.1 miti to 5 miti, in particular Contains or consists of 1 miti through 5 miti as measured by a microscopic imaging technique. 16. Use of a marker according to one of claims 9 to 15 for the identification of a polymer, preferably selected by a method from the group consisting of X-ray fluorescence, microscopic methods, spectroscopic methods and combinations thereof, the identification of the polymer being used in particular for i ) assign the polymer to a specific manufacturer, preferably to a specific batch from a specific manufacturer; and / or ii) to identify the polymer as part of a polymer recycling process; and / or iii) to separate the polymer from other polymers in the context of polymer recycling; and / or iv) document the history of the polymer. 17. Marked polymer, characterized in that it contains at least one marker, the marker containing or consisting of particles which contain or consist of a metal and / or a semimetal, the marker having at least three types of atoms that differ from one another Have atomic number, the marker being modified in particular geometrically and / or chemically modified. 18. Marked polymer according to claim 17, characterized in that the marked polymer can be produced by a method according to one of claims 1 to 8.